Neoamphimedine Circumvents Metnase-Enhanced DNA Topoisomerase IIα Activity Through ATP-Competitive Inhibition

Type IIα DNA topoisomerase (TopoIIα) is among the most important clinical drug targets for the treatment of cancer. Recently, the DNA repair protein Metnase was shown to enhance TopoIIα activity and increase resistance to TopoIIα poisons. Using in vitro DNA decatenation assays we show that neoamphim...

Full description

Bibliographic Details
Main Authors: Philip Reigan, Brian G. Reid, Qiong Zhou, Amanda K. Ashley, Jac A. Nickoloff, Robert Hromas, Daniel V. LaBarbera, Courtney L. Amerin, Qun Li, Adedoyin D. Abraham, Byong Hoon Yoo, Jessica Ponder
Format: Article
Language:English
Published: MDPI AG 2011-11-01
Series:Marine Drugs
Subjects:
Online Access:http://www.mdpi.com/1660-3397/9/11/2397/
Description
Summary:Type IIα DNA topoisomerase (TopoIIα) is among the most important clinical drug targets for the treatment of cancer. Recently, the DNA repair protein Metnase was shown to enhance TopoIIα activity and increase resistance to TopoIIα poisons. Using in vitro DNA decatenation assays we show that neoamphimedine potently inhibits TopoIIα-dependent DNA decatenation in the presence of Metnase. Cell proliferation assays demonstrate that neoamphimedine can inhibit Metnase-enhanced cell growth with an IC50 of 0.5 µM. Additionally, we find that the apparent Km of TopoIIα for ATP increases linearly with higher concentrations of neoamphimedine, indicating ATP-competitive inhibition, which is substantiated by molecular modeling. These findings support the continued development of neoamphimedine as an anticancer agent, particularly in solid tumors that over-express Metnase.
ISSN:1660-3397